Springfield daily republic. [volume] (Springfield, O. [Ohio]) 1887-1888, 1887-11-14
THE GREAT AMERICAN LAKES.
Where u" They Get Their supply Of
Water :-Chance of Level.

Where u" They Get Their supply Of
Water :-ChanG. of Level
II has long been known that the great
lake are subject TO remarkable and SEEM
ingly capricious changes of level. These
changes are roughly registered in the va
rving volume of the ST. Lawrencc-that
remarkable river. itself the outlet o. ::hi."se
great lakes and in sense continuation
and part of the lakes themselves. In
some years the st. Lawrence, which
drains watershed of over 100000
square miles is much fuller all summer
than in other years. 1t leaves Lake Erie
already broad river, forty feet deep.
At the great cataract Of Niagara it de-
sccnds with its enormous mass of nearly
400, 200 cubic feet of water in every sec
ond of time.
This almost incomprehensible mass of
water. the drainage or overflow of all the
great lakes. varies in volume with the
level of the lakes of which it is a part.
A Milwaukee paper gives some interest
ing facts relating to these mysterious
irregular tidal movements, or change Of
level. in Lake Michigan. This, the
second in size and depth Of these great
lakes-the largest bodies of fresh water
on the globe-is subject to strange fluctu-
atoms. being several feet lower in some
years than in others. Lake Michigan is
a deep lake-about a thousand feet deep,
or practically as deep as Lake Superior.
1t has been. it seems. for nearly thirty
years the practice of the government to
take daily measurements of the height Of
the water at Milwaukee. The water
which at that point (as the clinginS
memory of a plunge into it at the closs.
of July. 1919. still attests) is almost az
icv cold as it is at Mackinaw-is usually
a foot or two higher in summer than it is
in winter; but in some years the varia-
ton is equal to three or four feet. This
represents, on SO great body of water,
an enormous difference. Lake Superior
alone is almost as large as the great state
of Ohio. while Lake Michigan. the direct
receiver of its overflow, is about as large
as Massachusetts. Vermont and New
Hampshire put together. A change of
three or four feet in the level of these
great lakes implies a difference i'll the
amount Of water too great TO be fully
understood and appreciated. The other
lakes necessarily participate in these
fluctuations: but these appear to be most
marked in Lake Michigan.
Their cause is not yet wholly under
stood. Various theories have been ad-
vanced TO account for them-even to the
absurd extent of connecting them with
the ocean tidal movements. But a far
simpler explanation seems more probable
1t would seem that the higher level in
Lake Michigan in summer and autumn
may be caused by the spring and summer
rains and the late melting SHOWS of the
vast Canadian watershed which feeds
Lake Superior with its rushing streams
and copious rivers. In that immense lake
a rise of a single foot is equivalent to a
much greater rise in the lesser lakes of
the great system. That the fluctuations
should be irregular, showing far greater
level in some years than in others. might
well be due to the VARYING quantities of
May and June rain in different years,
and to the greater quantities of snow re-
naming in those hyperborean latitudes,
TO be only transformed, in Nav and June,
into water. Of course the influx received
by the larger lake would be far less in
winter-and hence the lakes would be
lowest in winter and highest in summer
and autumn. Whatever the cause NAV
be, the occurrence itself of these large
fluctuations in the levels of such vast
bodies of water is one of the striking facts
in the worlds greatest fresh water sys.
tenn. and well worthy Of philosophical
examination. That lake and river sys-
tenor perhaps it might be called all
one great river. 1000 miles long-is the
most interesting one on the globe. Its
greatest expansion-the vast Lake SUI
perior--is at level of over 600 feet above
the level of the sea; lake whose area is
1880 square miles. and whose depth is
LOCO feet. The river flows on its lordly
course through the rocks of the Lauren
tan system. the Oldest on the globe, and
it receives n, its afiluent the dark. wild
waters of the Hartford Times.